Automatic infeed mechanism



Jan. 13, 1948. w. MIGNONA 2,434,366

AUTOMATIC IIN-FEED MECHANISM Filed Nov. 27, 1946 Patented Jan. 13, 1948 UNETED STATES 'i' FFECE Claims.

This invention relates to grinding machines and is particularly directed to an automatic infeed attachment for such machines.

An object of the invention is to provide automatic means to actuate the hand feed lever of a grinding machine in such a :manner that uniform stock removal from the 'piece being ground is insured.

Another object of the invention is to provide an automatic in-feed attachment for machines of this type which can be easily installed Without a1- tering the basic structure of the machine.

A further obi ect of the invention resides in the provision of an hydraulic feed attachment, rendered effective upon partial movement of the hand feed lever, to move the feed lever through its feed range to stop position.

Further objects and advantages will become apparent from a study of the following description when taken in connection with the accompanying drawing in which:

Figure 1 is a front elevation of a grinding machine incorporating the invention;

Figure 2 is a fragmentary end View of the machine shown in Figure 1;

Figure 3 is an enlarged sectional detail of the catchblock;

Figure 4 is an enlarged sectional detail of the valve structure of the mechanism;

Figure 5 is a side elevation of the cylinder with parts broken away and others shown in detail; and

Figure 6 is an enlarged view of a modified form of cam,

Referring to the drawing, the numeral I0 indicates a centerless grinding machine which incorporates the present invention. The machine I0 is provided with a hand in-feed lever I2 capable of causing relative movement between a pair of grinding wheels I4 and I5, between which the piece being ground is positioned and rotated during the grinding operation. When the hand lever is manually operated throughout its entire feed range, the operator is obliged to use extreme caution to prevent erratic movement which causes an uneven rate of stock removal resulting in certain heat-tempering of the hardened work surfaces resultingr in loss of metallurgical quality.

To overcome the undesirable features of manual operation, the machine Ill has been provided with automatic means to operate the lever I2 during its feed movement. The automatic means, preferably in the form of an attachment readily applied to grinding machines of the type illustrated, comprises a cylinder i8 conveniently attached to the machine by means such as the bracket 2Q. The cylinder I8 contains a piston I9 of suitable form having a piston rod 22 extending from the cylinder into the path of movement of the lever I2, the bracket 2S being aiXed to the machine to so locate the cylinder and piston rod. The outer end of piston rod 22 is provided with a catch-block 2li, shown in detail in Figure 3. Catch-block 2li is provided with a notch 25 for receiving a slide bracket 2i mounted on the lever l2, means in the form of oppositely disposed spring pressed poppets 29 projecting into notch 25 serving to latch the bracket 2'I and block 24 together when the lever is moved into position to permit such engagement.

Connected to the top and bottom of cylinder I8 are fluid supply pipes 3l and 32 respectively, leading from a two-way control valve 35 of a well known type, which is in turn connected to a source of hydraulic fluid under pressure. The source of hydraulic pressure may be provided by the grinding machine itself and is suiiicient to actuate the feed mechanism, As illustrated in Figure 4, the valvef: contains a spring pressed piston or plunger 3i which permits iiuid iiow to one cylinder port while exhausting the other port. The plunger is actuated by means of a cam 40 mounted on the base of the hand feed lever I2, the cam being located so as to engage the plunger 31 simultaneously with the engagement of slide bracket 2'! and block 24. Thus, the valve 35 is actuated to supply fluid to the top of cylinder I8 upon interlocking of the lever I2 with the piston rod 22 to move the lever I 2 through its feed range. The use of hydraulic fluid for this purpose insures smooth constant feed and avoids the undesirable features of the manual feed.

In order to unlatch the slide bracket 21 from the catch block 2d. the stroke of the piston I9 is such that lever I2 engages and is stopped by bracket 2l! prior to completion of the downward movement of the piston I9. At this limit of the feed movement` the operator can raise the lever I2, to return the lever to starting position which movement also disengages the cam 40 from the valve plunger 3l. Plunger 31 returns to the position shown in Figure 4 to exhaust vfluid from the top of cylinder i3 and supply uid to the bottom of the cylinder which action moves the piston rod 22 to its starting position, again putting the catch-block 2d into feed position.

The contour of cam All is such that the stock removal from the piece being ground is continuous and at a predetermined rate. In order to vary the feed in instances where a continuous, uninterrupted grinding operation would produce undesirable heat tempering of the hardened surfaces, the cam may be modified as shown in Figure 6. Cam 40 is illustrative of an arrangement for interrupting the grinding action at predetermined intervals to permit periodic cooling of the piece. Thus, it will be understood that by forming the cam of pre-calculated contour, any practical rate and degree of stock removal may be obtained.

What I claim is:

1. The combination With a grinding machine having a hand feed lever, of a cylinder, a fluid actuated piston in said cylinderhaving a piston rod projecting from said cylinder into the path of said hand feed lever, interlocking elements Vassociated respectively with said piston-rod and-hand feed lever engageable upon movement of said hand feed lever toward feed position, a valvefor controlling the ow of uid to said cylinder,

:means associated with said hand feed lever for .actuating said valve simultaneously with the engagement of said interlocking elements to cause said piston to move said hand feed lever through :its feed range to stop position, and means to release said interlocking elements so that said hand `feed `lever may be moved to starting positionJ such movement releasing said valve actuating means to cause said piston rod to return to starting position.

2. The combination with a grinding machine Ahaving a hand feed lever, of a cylinder, a uid actuated piston in said cylinder having a piston `rod projecting into the path of movement .of said lever, interlocking elements associated respectively with said piston rod and said lever engageable -upon movement of said lever toward feed position, a valve for controlling the flow of fluid to and from said cylinder, a cam associated with -said lever for actuating said valve simultaneously with the engagement of said interlocking elements to cause said piston to movesaid lever through its `feed range, and means to release said interlocking elements at the limit of feed movement of said lever to permit said lever to be manually moved `to starting position and disengage said cam from said valve to cause said piston to return to starting position.

3. The combination with a grinding machine having a hand feed lever, of a cylinder, a fiuid actuated piston in said cylinder having a piston rod projecting from said cylinder into the path of said hand feed lever, interlocking elements associated respectively With said piston rod and hand feed lever engageable upon movement of said hand feed lever toward feedrposition, a, valve for controlling the flow of uid to said cylinder, means associated with said hand feed lever for actuating said valve simultaneously with the engagement of said interlocking elements to cause said piston to move said hand feed lever at a uniform rate through its feed range, and means to automatically release said interlocking elements at the limit of feed movement of said hand feed lever.

4. In combination with the hand feed lever of a grinding machine having a source of hydraulic -iiud under pressure, hydraulically actuated means connected to said source for moving the hand feed lever including a cylinder, a piston in said cylinder having a piston rod projecting into the path of movement of said lever, interlocking elements ,associated with said piston rod and said lever engageable upon movement of said lever to- Ward feed position, said piston serving 4to move said lever at a uniform rate through its feed range, and means to release said elements at the limit of feed movement of said lever.

5. In combination with the irl-feed mechanism of a grinding machine, va cylinder, a fluid actuated piston in said cylinder having a piston rod adapted to be releasably connected to said mechanism, a valve for controlling the ow of fluid to and from said cylinder, a cam for actuating said valve simultaneously with the connection of said piston rod to said mechanism to move the latter through its feed range, and means to release said piston from said in-feed mechanism at the limit of its feed movement and disengage said cam from said valve to cause said piston to return to starting position.

WILLIAM MIGNONA. 

